JP2020119194A - Drive response monitoring device - Google Patents

Abstract

To provide a drive response monitoring device which detects a change in speed control response of a drive device, and which determines an abnormality and a deterioration.SOLUTION: A drive response monitoring device according to an embodiment includes: a data collecting device that collects, in time-series, multiple pieces of past record data including control signals, etc., relative to devices, etc., in a process control system; a response measuring device which collects, in time-series, the speed command values of the drive device and the actual measured values of the speed, and which measures a speed control response that is a delay in the actual measured value relative to the speed command value at an arbitrary time; and a cluster classifying device that classifies the pieces of time-series data of at least the two pieces of past record data selected among the multiple pieces of past record data so as to have the same value, respectively, at different time. The cluster classifying device compares the data on the speed control response having the times contained in the at least two pieces of past record data with a reference value, and determines the propriety of the data on the speed control response.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to a drive response monitor that monitors speed control responses of motors and drives in a process control system.

The plant production line is operated by a process control system. The process control system includes a motor for driving equipment, a drive system for controlling the motor, a programmable logic controller (hereinafter referred to as PLC), and the like. There are various operation performance signals (control signal, sensor signal, operation signal, etc.) in the process control system. The data acquisition system can store these signals as time series data. The accumulated time series data can be effectively used and utilized by using an appropriate system. Therefore, there is a need to use these data for monitoring and maintenance of the plant.

Patent Document 1 describes a method of dividing time-series data into clusters by principal component analysis and modeling a target for each cluster to constantly evaluate the performance deterioration state of equipment constituting a plant. ing.

In Patent Document 2, by using two correlated time series data, a model for estimating one from the other is created, and a value output from the estimated model and actual time series data are compared. , A method for steadily evaluating the performance deterioration state of equipment constituting a plant is described.

Japanese Patent No. 5048625 Japanese Patent No. 5669553

In the above-mentioned Patent Documents 1 and 2, etc., a plant model is created, and an abnormality of the equipment is detected by making some determination with respect to the deviation from the estimated value by the model. However, such modeling requires a huge amount of data, and in order to obtain an accurate model with less error, it is necessary to determine in advance whether the data used for model creation is normal or abnormal. It takes a lot of time and effort.

An embodiment is to provide a drive response monitoring device that determines abnormality or deterioration from changes in speed control response of a motor and a drive device without creating a plant model that requires a great deal of time and labor. And

A drive response monitoring device according to an embodiment includes a data collecting device that collects a plurality of performance data including control signals and measurement data related to devices and products operated by a process control system in time series, and a drive that drives a motor. Response for collecting a speed command value of the device and a measured value of the speed of the motor with respect to the speed command value in a time series, and measuring a speed control response which is a delay of the measured value of the speed with respect to the speed command value at an arbitrary time. A measurement device and a cluster classification device that classifies time-series data of at least two performance data selected from the plurality of performance data into clusters so as to have the same value at different times. The cluster classification device associates the data of the speed control response having times included in the at least two performance data classified into the cluster with the cluster, and collects the data of the speed control response associated with the cluster, The quality of the data of the speed control response is judged by comparing with a preset first reference value.

In the present embodiment, a drive response monitoring device that detects changes in the speed control response of the motor and the drive device and determines abnormality or deterioration is realized without requiring a great deal of time and labor.

FIG. 3 is a block diagram illustrating a drive response monitoring device according to the first embodiment. 3 is an example of a schematic operation waveform relating to the drive response monitoring device of the first embodiment. FIG. 4 is a schematic diagram for explaining the operation of the drive response monitoring device of the first embodiment. FIG. 14 is a schematic diagram for explaining the operation of the drive response monitoring device of the third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each portion, the size ratio between the portions, and the like are not necessarily the same as the actual ones. Even if the same portion is shown, the dimensions and ratios may be different depending on the drawings.
In the specification and the drawings of the application, components similar to those described in regard to a drawing thereinabove are marked with like reference numerals, and a detailed description is omitted as appropriate.

(Embodiment 1)
FIG. 1 is a block diagram illustrating a drive response monitoring device according to this embodiment.
As shown in FIG. 1, the drive response monitoring device 15 is connected to the communication network 4. A process control system 5 is connected to the communication network 4. The process control system 5 includes a programmable logic controller (PLC) 3. The PLC 3 controls the drive device 1 according to the set program. The drive device 1 drives the motor 2 according to the control signal and the command supplied from the PLC 3.

The drive device 1 and the motor 2 are provided in plural sets in, for example, a steel rolling plant. A plurality of sets of drive device 1 and motor 2 drive, for example, a rolling mill, drive table rollers, and drive a pump for pumping cooling water.

The PLC 3 collects control signals for driving actuators and the like related to process control other than the drive device 1 and the motor 2 and measurement data from various measuring instruments including a measuring instrument provided in the drive device 1. The process control system 5 can accept a manual operation by these operators from, for example, an operation panel or an HMI terminal (not shown) connected to the communication network 4.

The PLC 3 handles these control signals and measurement data. These control signals and measurement data are referred to as an operation result signal group 9. The operation performance signal group 9 can include a process performance value 6, an operation parameter 7, an operator operation signal 8, and the like.

The process performance value 6 refers to a performance value in each step of a product including an intermediate product manufactured by being controlled by the process control system 5. For example, PLC3 acquires the data of the rolling load measured by the load cell provided in the rolling mill as the actual rolling load value. The PLC 3 acquires the tension data obtained by measuring the tension of the rolled material directly by a tensiometer or indirectly by using actual measurement data such as speed and torque as the actual tension value. The PLC 3 acquires the output torque data recorded by the drive device 1 as the actual torque value.

The operation parameter 7 is data relating to the specifications of the product set by the host process computer. The PLC 3 can acquire these data via various measuring instruments provided during the process. For example, before and after the rolling mill, measuring instruments for measuring the strip thickness and strip width of the rolled material are provided, and data is generated in real time from these measuring instruments. The steel grade is set by the process computer.

The operator operation signal 8 is an operation signal including a manual operation from a control panel, an HMI terminal or the like connected via the communication network 4. The operator operation signal 8 includes, for example, the result of the operation article intervention operation by the HMI terminal and the result of the mode selection operation.

The above-mentioned operation result signal group 9 is an example in the case of being applied to the process control system 5 of the rolling process of steel or the like, and is not limited to these. Appropriate signal groups are set according to the manufacturing process of non-ferrous metal and other manufacturing processes such as paper and film.

Further, the operation result signal group 9 is not limited to a single PLC, but may be collected via a plurality of PLCs forming the process control system. Further, the operation result signal group 9 may be collected from another system that constitutes the process control system, such as a distributed control system (DCS).

The drive response monitoring device 15 collects each performance data of the operation performance signal group 9 handled by the PLC 3 via the communication network 4. The acquisition time is associated with each performance data of the operation performance signal group 9. That is, each performance data of the operation performance signal group 9 is collected as time-series data acquired in real time. Each actual data collected as time-series data is not associated with the final product, but as will be described later, it is classified into clusters by the unit of time and changes in the speed control response of the drive device 1 and the motor 2. Used to monitor.

The configuration of the drive response monitoring device 15 will be described.
The drive response monitoring device 15 includes a data collection device 10, a response measurement device 11, and a cluster classification device 12. The data collection device 10 and the response measurement device 11 can be connected to the communication network 4. The data collection device 10, the response measurement device 11, and the cluster classification device 12 are connected to each other.

The data collection device 10 collects each performance data of the operation performance signal group 9 handled by the PLC 3 via the communication network 4 in real time. The data collection device 10 supplies all the performance data of the operation performance signal group 9 or a plurality of performance data selected from the operation performance signal group 9 to the cluster classification device 12 as time series data. When selecting a plurality of performance data from the operation performance signal group 9, the performance data to be selected is set in advance.

The response measurement device 11 collects, in real time, time series data regarding the response of the drive device 1 handled by the PLC 3 via the communication network 4. The time-series data regarding the response of the drive device 1 is data representing the respective time changes of the speed command value data generated by the PLC 3 and the actual speed data. The data of the speed command value is generated by the PLC 3 based on the data of the rolling speed pattern supplied from the upper process computer, for example. The actual speed data is data measured by the tachometer provided in the motor 2 when the drive device 1 operates according to the speed command value. More specifically, the difference between the speed command value and the measured speed value is defined as a speed control response, and the response measuring device 11 supplies data of the speed control response to the data collecting device 10.

The cluster classification device 12 includes a cluster group 13 and a determiner 14. The cluster group 13 includes a plurality of clusters. The cluster classification device 12 classifies the performance data selected from the operation performance signal group 9 into a plurality of clusters. The cluster classification device 12 classifies the selected actual data having the same value at different times into the same cluster. The data of the speed control response at the same time as the time included in each classified cluster is associated with that cluster.

As will be described in detail later, when the selected actual data has the same value at different times, it means that the operating conditions are the same, so the speed control response at each time is compared with the reference value. As a result, the status of abnormality or deterioration of the drive device 1 or the motor 2 can be determined.

In the determiner 14, a reference value (first reference value) relating to the speed control response for each cluster is preset. The determiner 14 compares the data of the associated speed control response with the reference value in the same cluster to determine whether or not it exceeds a predetermined value or range. In a certain cluster, when the data of the speed control response exceeds a predetermined value or range of the reference value, it indicates that the drive device 1 or the motor 2 is abnormal or deteriorated. For example, a plurality of predetermined values or ranges of the reference value may be provided to determine the degree of deterioration and abnormality.

The operation of the drive response monitoring device 15 of this embodiment will be described.
FIG. 2 is an example of a schematic operation waveform relating to the drive response monitoring device of the present embodiment.
The drive device 1 uses the speed actual measurement sensor attached to the motor 2 or the actual speed value obtained from the actual speed estimator inside the drive device 1 in accordance with the speed command value output from the PLC 3 to drive the motor. 2 speed control is performed.

The PLC 3 includes a process actual value 6 such as a rolling load actual result, a tension actual result, and a torque actual result, an operation parameter 7 such as a plate thickness, a plate width, and a steel grade, and an operation result including an operator operation signal 8 such as an intervention operation from the operation article or a mode selection The signal group 9 is input as a control signal. The PLC 3 enables these control signals to be used by the data collection device 10 and the response measurement device 11 via the communication network 4.

The data of the speed control response measured by the response measuring device 11 is collected as time series data by the data collecting device 10 together with the operation result signal group 9 via the communication network 4.

FIG. 2 shows a graph of the speed characteristic of the drive device 1 in which the horizontal axis represents time and the vertical axis represents the speed of the motor 2. In FIG. 2, the solid line indicates the time change of the measured value Nm of the speed data of the motor 2 driven by the actual output of the drive device 1. The broken line shows the time change of the speed command value Nref supplied from the PLC 3 to the drive device 1.

As shown in FIG. 2, in the drive device 1, the speed command value Nref is set to increase almost linearly from 0 and reach the target value. The actual speed Nm of the motor 2 increases so as to follow the speed command value Nref and reaches the target value. The actual speed Nm has a delay time with respect to the speed command value Nref, and this delay time is defined as a speed control response.

The speed command value Nref and the actual speed Nm are time series data. In this example, N1 is set to the value of k[%] of the actual speed Nm. k[%] is preset such as 20%. The time of the actual speed Nm at the speed N1 is t2. Further, the time of the speed command value Nref at the speed N1 is t1. In this way, the speed control response (t2-t1) is associated with the time t2.

FIG. 3 is a schematic diagram for explaining the operation of the drive response monitoring device of the present embodiment.
FIG. 3 shows, as an example, time series data of the rolling load actual result and the tension actual result in the operation result signal group 9 associated with the time. In this figure, the times are indicated by t1 to tm+k, the actual rolling load data is indicated by a1 to am+k, and the actual tension data is indicated by b1 to bm+k. The rolling load actual data and the tension actual data are respectively associated with the time, and the association is represented by the same subscript. It should be noted that the larger the subscript, the later time is shown, and the intervals between the times are constant. Further, in this example, data of speed control responses ΔTi and ΔTm+i associated with a specific time is also shown.

The cluster classification device 12 classifies the clusters into clusters by using the performance data preselected from the operation performance signal group 9. For example, the cluster classification device 12 creates a plurality of rolling load actual data and tensile actual data for each steel type to form a cluster group 13. The cluster classification device 12 stores, in the cluster, a speed control response that has been converted into time-series data and that has the same time as the time of the data stored in the cluster. The quality of the speed control response for each cluster is determined by the determiner 14.

The clusters classified as described above have the same operating conditions. Therefore, the speed control response data stored in the same cluster can be considered as the speed control response data under the same operating condition.

Here, if the equipment controlled by the process control system 5 is normal, the speed control response under the same operating conditions should be the same. Therefore, when the speed control response within the same cluster is out of a limited range, it can be determined that there is some abnormality in the equipment. At this time, by finely dividing the cluster, the abnormality determination of the equipment can be made finer and the sign of the abnormality can be detected.

As shown in FIG. 3, in this example, one cluster formed in the cluster group 13 includes time series data of two sections T1 and Tm+1. The two sections T1 and Tm+1 have the same length.

The time series data a1 to ak and b1 to bk included in the section T1 have the same values as the time series data am+1 to am+k and bm+1 to bm+k included in the section Tm+1. In the figure, the data surrounded by the solid line frame in the section T1 is equal to the data surrounded by the solid line frame in the different section Tm+1, as connected by the broken line arrow. For example, the data a1 and b1 associated with the time t1 have the same values as the data am+1 and bm+1 associated with the different times tm+1, respectively. Similarly, the data a2 and b2 are equal to the data am+2 and bm+2, respectively, and the data ai and bi are equal to the data am+i and bm+i, respectively.

The respective clusters in such sections T1 and Tm+1 are treated as the same cluster. In the same cluster, the operating conditions are the same, and in each of the sections T1 and Tm+1, the speed control response can be considered to be the same value under the operating conditions.

Here, when there are speed control responses ΔTi and ΔTm+i respectively associated with time ti and time tm+i, since they are speed control responses under the same operating conditions, unless the drive system has a problem, the speed control responses ΔTi and ΔTm+i are It is considered that they are the same value. Conversely, if there are differences in the speed control responses ΔTi and ΔTm+i in the same cluster, it can be considered that the drive system has some problem such as abnormality or deterioration.

By setting the same range of the speed control response in advance and comparing the speed control response at any time within the same cluster as the determination standard with this determination standard, the drive device 1 and the motor 2 are checked for abnormality or deterioration. The situation can be determined.

In the cluster classification, the above section can be set arbitrarily. The determination may be made based on the presence or absence of the same data value in a wider section, or may be determined based on the same presence or absence of data in a narrower range, for example, a single time.

The effects of the drive response monitoring device 15 of this embodiment will be described.
The drive response monitoring device 15 of this embodiment includes a data collecting device 10 that collects the time-series data of the operation result signal group 9 of the process control system 5 in real time. The drive response monitoring device 15 can collect time-series data regarding the speed response of the drive of the motor 2 from the drive device 1 in real time. Therefore, the speed control response data can be associated with each data of the operation result signal group 9 depending on the data acquisition time.

The drive response monitoring device 15 includes a cluster classifying device 12 that classifies each data of the operation result signal group 9 and the data of the speed control response, which are associated with each other by time, into clusters by having the same value at different times. The cluster classification is executed so that all the time-series data of the operation result signal group 9 or a plurality of selected time-series data are the same data at the same time or in the same period. Therefore, since the time-series data classified into the same cluster represents the same operating condition, it is possible to judge the quality of the speed response under the same operating condition.

(Embodiment 2)
In the above-described first embodiment, whether or not the speed control response is within a certain limited range is used as the determination criterion. However, since the speed control response may change due to the maintenance of the equipment, it is necessary to take into account the change in the speed control response due to this maintenance in advance in the judgment criterion used for the quality judgment. That is, it means that the range of the criterion of the speed control response is wider than that in the case where the change due to the equipment maintenance is not included. Therefore, in such a case, even if the number of types of operation data of the operation result signal group 9 used for cluster classification is increased and the cluster is finely divided, it is difficult to perform the equipment abnormality determination with high accuracy. Become.

Therefore, the second embodiment is not limited to the quality determination of the speed control response at a specific time, and introduces a criterion for the time change of the speed control response. The speed control response for each cluster is continuously collected and its temporal change, that is, the secular change is noted. More specifically, the steepness of the change between speed control responses at each time collected for each cluster is calculated and compared with a preset determination reference value.

For example, the cluster classification device 12 associates the speed control response ΔT1 at the time t1 with the cluster C1 including the time t1. Similarly, the cluster classification device 12 associates the speed control response ΔT2 with the cluster C1 at the time t2. That is, in the cluster C1, the speed control response ΔT1 at time t1, the speed control response ΔT2 at time t2,..., The speed control response ΔTi at time ti, the speed control response ΔTi+1 at time ti+1,. Are categorized, and each actual result data is associated by time.

At this time, changes in the speed control responses ΔTi and ΔTi+1 with respect to a time change between adjacent times ti and ti+1 in the cluster C1 are compared with a determination reference value (second reference value) ΔTth.

(ΔTi+1-ΔTi)/(ti+1-ti)>ΔTth (1)

When Expression (1) is satisfied, it is determined that the rapid deterioration determination is in progress, and the determiner 14 outputs the deterioration determination.

In the drive response monitoring device of the second embodiment, the cluster classifying device 12 continuously acquires the data of the speed control response for each cluster, so that the time change of the speed control response corresponding to each adjacent time suddenly occurs. It can be determined whether it is a thing or not. Therefore, it is possible to eliminate the detection of a slow change in the speed control response as in the case of recovering the speed control response that has deteriorated due to natural deterioration over time due to maintenance or the like. Deterioration can be determined.

Of course, the time change of the speed control response may be determined while the speed control response is determined at each time (in the case of the first embodiment).

(Embodiment 3)
In the other embodiment described above, the cluster classification device 12 preliminarily selects a plurality of performance data from the operation performance signal group 9 and classifies the clusters according to the selected performance data. However, selecting what kind of performance data from the operation performance signal group 9 may require a human judgment based on experience. Therefore, in the third embodiment, the selection of necessary performance data from the operation performance signal group 9 is automated.

In the drive response monitoring device according to the third embodiment, the cluster classification device 12 automatically generates a cluster in order to determine the quality of the speed control response from the operation result signal group 9.

The data collection device 10 stores all time-series performance data of the operation performance signal group 9. The data of the speed control response is stored in association with the time. When the data of the speed control response has the same value, the operating conditions are the same at the time when the data of the speed control response is acquired.

The same operating condition will be classified into the same cluster. Therefore, by extracting a common condition from the record data associated with the time when the same speed control response is acquired, it is possible to select the record data required for cluster generation.

FIG. 4 is a schematic diagram for explaining the operation of the drive response monitoring device of the present embodiment.
FIG. 4 shows the time-series data of all the performance data ai, bi, ci,..., xi, yi, zi included in the operation performance signal group 9. The record data ai, bi, ci,..., xi, yi, zi are associated with the time ti. Here, i is a natural number (integer of 1 or more), and represents i-th time ti and actual data ai, bi, ci,..., xi, yi, zi.

Further, the speed control response data is acquired at an arbitrary time, and the speed control response data is associated with the actual result data via the time.

Here, when the speed control responses ΔTm and ΔTn acquired at different times tm and tn have the same value, the set of actual data am, bm, cm,..., Xm, ym, zm and an, bn, cn,..., Xn, yn, zn are considered to be actual data acquired under the same operating conditions. However, these performance data may include data not related to the setting of the operating conditions. Therefore, it is necessary to search for a common condition among the set of actual data am, bm, cm,..., Xm, ym, zm and an, bn, cn,..., Xn, yn, zn. The common condition is, for example, when the values of the actual data are equal to each other.

Of the sets of actual data am, bm, cm,..., Xm, ym, zm and an, bn, cn,..., Xn, yn, zn, the set of data bm, cm and the data bn surrounded by a solid line frame. When the sets of cn have the same value, it is determined that these performance data sets this operating condition. The cluster classification device 12 extracts arbitrary performance data bi and ci from the operation performance signal group 9, and classifies clusters when the performance data bi and ci have the same value at different times. After that, the cluster classification device 12 operates in the same manner as in the other embodiments described above.

Regarding the setting conditions of the same operating condition, the time range associated with the data having the same value may be further widened. For example, when the values of the set of data bm and cm are equal to the values of data bn and cn, respectively, the time is returned by one, and the data at time tm-1 and the data at time tn-1 are compared and the same. The operating conditions may be determined.

According to the embodiment described above, it is possible to realize a drive response monitoring device that can determine changes in the speed control response of a motor and a drive device without requiring a lot of time and labor.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and equivalents thereof. Further, the above-described respective embodiments can be implemented in combination with each other.

1 drive device, 2 motors, 3 programmable controller, 4 communication network, 5 process control system, 6 process actual value, 7 operation parameter, 8 operator operation signal, 9 operation result signal group, 10 data collecting device, 11 response measuring device, 12 cluster classifier, 13 cluster group, 14 judging device, 15 drive response device

Claims (4)

A data collection device that collects, in time series, a plurality of actual data including control signals and measurement data related to devices and products operated by a process control system.
A speed control that is a delay of the speed command value of the drive device that drives the motor and the measured value of the speed of the motor with respect to the speed command value in time series, and is the delay of the measured value of the speed with respect to the speed command value at any time. A response measuring device for measuring the response,
A cluster classification device that classifies time-series data of at least two performance data selected from the plurality of performance data into clusters so as to have the same value at different times.
Equipped with
The cluster classification device,
Associating the data of the speed control response with the time included in the at least two performance data classified into the cluster with the cluster,
A drive response monitoring device that compares the speed control response data associated with the cluster with a preset first reference value to determine pass/fail of the speed control response data. The drive response monitoring device according to claim 1, wherein the cluster classification device sets the first reference value at a single time to determine whether the data of the speed control response is good or bad. The drive response monitoring device according to claim 1 or 2, wherein the cluster classification device compares a change in the performance data in two different time ranges with a preset second reference value. The cluster classification device extracts the speed control responses having the same value and, among the plurality of performance data associated with the times of the extracted speed control responses having the same value, has the same value at different times. The drive response monitoring device according to claim 1, wherein the drive response monitoring device is classified into clusters so as to form a set of data.

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